tested with karaf 18.1

In yang model we have a leaf declared as the following

leaf myLeaf {     
  type string {
    length "1..4";
  }
}

Case 1)

The leaf is filled with the value="    "

i.e. with four empty spaces:

<myLeaf>    </myLeaf>

ODL raises an error for this case,

because all spaces are removed and the length constraint is not satisfied.

Case 2)

The leaf is filled with four empty encoded spaces, each space is encoded using a xml entity, using & plus #160;

ODL does not raise error,

but the json return by ODL

contains non printable characters,

the encode spaces are not decoded back to plain spaces ...